Fix fast/custom-elements/custom-element-registry-wrapper-should-stay-alive.html so that it doesn't timeout on debug bots.
Committed r234618: <https://trac.webkit.org/changeset/234618>
Created attachment 346659 [details] Fixes the test
Committed r234621: <https://trac.webkit.org/changeset/234621>
https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=fast%2Fcustom-elements%2Fcustom-element-registry-wrapper-should-stay-alive.html
Committed r234638: <https://trac.webkit.org/changeset/234638>
<rdar://problem/42988535>